This application proposes that the Maternal-Fetal Medicine Unit of the University of Cincinnati Medical Center (UCMC) be selected for the Cooperative Multicenter Network of Maternal-Fetal Medicine Units (MFMUs). The Maternal-Fetal Medicine Unit of the University of Cincinnati Medical Center is particularly well suited for collaboration and cooperation with other Maternal-Fetal Medicine units and with NICHD staff to establish research protocols, uniform data formats, and data transfer. The Maternal-Fetal Medicine Unit at the University of Cincinnati has demonstrated an excellent tradition of close cooperation among Neonatology, Endocrinology, Biostatistics and Epidemiology during the planning and implementation of the Diabetes in Pregnancy Program Project Grant, the NIH Perinatal Emphasis Research Center for the study of intrauterine growth retardation, and the Perinatal Research Institute. Over 2600 primary and referred patients are delivered at the MFMU of UCMC each year with greater than 40% being high risk, 51% white and 20% private. Professional staffing of the MFMU of UCMC is provided 24 hours a day by four board certified or eligible MFM specialists and five MFM fellows. Multidisciplinary cooperation for perinatal care includes neonatal care, genetics, internal medicine, laboratory medicine and social services. Level I and II obstetrical ultrasound, antenatal testing, and sophisticated laboratory analysis are available to the MFMU 24 hours/day. Previous and ongoing experience in multidisciplinary clinical research trials including complex data formatting, entry, and analysis assures valuable contributions by the MFMU of UCMC to the Cooperative Multicenter Network of MFMUs. The Maternal-Fetal Medicine faculty and services at UCMC are complemented by a nationally renowned Neonatal faculty committed to the concept that important and unresolved issues of perinatal care can only be solved by carefully planned prospective clinical trials. Not only do the two faculty enjoy strong clinical, research and training links, the Greater Cincinnati Metropolitan region is unique in that there is well established and successful Perinatal-Neonatal Outreach Program which ensures referral of all complicated pregnancies to the MFMU at UCMC. The commitment of UCMC and the Childrens' Hospital Medical Center (CHMC) to research is further exemplified by the creation four years ago of the 35 investigator Perinatal Research Institute whose efforts are exclusively devoted to perinatal and developmental research.